Underreamer.



J, C. SWAN.

UNDERREAMER.

APPLICATION FILED OCT 26, 1909.

9'7 9 1 O6, Patented Dec. 20, 1910 3 SHEETS-SHEET l. FIE. 1, F155. FIE.E.

5' INVENTOR W 1 TNESSES J. G. SWAN UNDERRBAMER.

APPLICATION FILED OCT 26, 1909 FIL -l,

5's WIZVESSES [NVENTOR J. G SWAN.

UNDERREAMER.

APPLIOATION FILED OUT 26, 1909.

Patented Dec. 20, 1910.

3 BHBET8BHEET 3.

Fill/l.-

WITNESSES [NVENTOR BY /W GSWM W QM MW UNITED STATES PATENT OFFICE.

JOHN C. SWAN, OF MARIETTA, OHIO.

UNDERREAMER.

To all whom it may concern:

Be it known that I, JOHN C. SWAN, a citizen of the United States,residing at Marietta, in the county of \Vashington, State of Ohio, haveinvented certain new and useful Improvements in Underreamers, of whichthe following is a description, reference being had to the accompanyingdrawings, forming a part hereof.

My invention relates to devices for reaming out or enlarging well holesand particularly to devices for such purpose adapted for under reamingthat is reaming out or enlarging the well hole drilled below casing inorder to permit the casing to be lowered. My invention is an improvementon the underreamer for which Letters Patent No. 683,352 were issued tome September 24, 1901, and it consists in the construction andcombination of devices hereinafter described and particularly pointedout in the claims.

In the under-reamer of my patent referred to the wedge on which thereaming bits or slips move from retracted position to expanded positionis a straight wedge of uni- .form taper throughout and the degree ofexpansion given to the reaming bits or slips is necessarily limited bythe length of the wedge and this in turn is necessarily limited by thedistance through which the spring for moving the reaming bits or slipsfrom contracted to expanded position can be depended on for effectivework, as well as by the length of tool which is .found to Y be suitablefor practical use.

It is sometimes found desirable to enlarge the hole drilled belowcasing. for a portion or all of its length. to a diameter greater thanthat to which the reaming bits or slips I of an underreainer such as isdisclosed in my patent referred to will expand, the underreamer being ofsuch dimensions as to pass through the casing when the reaming bits orslips are at the lower end of the wedge.

It is the purpose of my present invention to provide an underreamerwhich will be adapted to be used to enlarge the hole drilled belowcasing either to standard size or to a considerably larger size ifdesired.

It is a further purpose of the invention to provide an improved meansfor holding the reamingbits or slips in contracted position while thetool is being lowered through the casing.

Referring to the drawings: Figure 1 is a Specification of LettersPatent.

Application filed October 26, 1909.

Patented Dec. 20, 1910.

Serial No. 524,731.

vertical sectional view through the lower portion of the reamer body ona plane at right angles to the faces of the wedge, showing the reamingbits or slips in contracted position. Fig. 2 is a similar view showingthe reaming bits or slips in expanded or working position. Fig. 3 is aview in longitudinal section of the upper end of the reamer body alsoshowing in elevation the double pin substitute by which the underreameris connected with the string of tools. Fig. 4 is an elevation of thelower portion of the reamer body showing the reaming bits or slips inretracted position. Figs. 5 and 6 are cross-sections'on lines wa2 and 3of Fig. 2. respectively. Figs. 7 and 8 are side and front viewsrespectively of the reaming bit or slip. Fig. 9 is a detail view of adevice foriret aining the reaming bits or slips in contracted position.Fig. 10 is a'vertical section similar to Fig. 2 showing an underreamerhaving a bit at its lower end. Fig. 11 is a side elevation of thecombined underreamer and bit shown in vertical section in Fig. 10. Fig.12 is a cross-section on line a-a of Fig. 1.

In the drawings, 1 is the reamer body having its lower portion sha'pedtoform a wedge/2 and having itsupper portion bored out to form a springcase 8. The upper end of 'thebore of the spring caseis tapered andscrewthreaded as shown at 4 to receive the tapered pin 5 of the doublepin substitute 6. The bore of the spring case 3 is of sufiicientconstruction disclosed in my patent above referred to, has the upperportion 14 of each of its faces at a different angle, relative to theaxis ofthe reamer body, from that of the lower portion '15 of thesesurfaces. The upper portions 14 of the wedge surfaces are v diameter toreceive the spring 7 which bearsat its lower end against a shoulder 8and bears at its upper end agalnst a head 9 on at a comparatively slightangle to the axial 14 I provide abutments 17 each navin its facearranged preferably at an ob ique angle to the' axial line of the reamerbody instead of at a right angle thereto.

Through the wedge at right angles to the wedge surfaces is formed alongitudinal slot 18 extending from apoint near the abutment 17 nearlyto the lower end of the wedge, the slot being of such width as to permitthe crossbar 13 to extend through it and to travel freely in it.

The materialof the reamer body extends outward at the sides of the wedgesurfaces to form housings 19 and in. these housings are formed guideribs 20 for guiding the reaming bits or slips. These guide ribs 20extend from the abutments 17 downward to, a point below the line of thepoint 16 and preferably extend nearly or quite to the lower end of thewedge. These guide ribs extend in a line parallel with the uppersurfaces 14 of the wedge to a point 21 somewhat below the point 16 atwhich the upper and lower surfaces 14 and 15 come together, and from thepoint 21 'to the lower end the rib, while following the generaldirection of the lower surface 15 of the wedge, is preferably nearer theplane of the surface 15 at its lower than at its upper end. It will beseen that by reason of this construction the space 22 between the sur--face of the wedge and the rib 20 is of uniform width from the abutment17 to the point 16 and froin this point to the point 21 downward is ofincreasing width and from the point 21 to the lower end of the rib is ofgradually decreasing width.

23 are the reaming bits or slips having their upper ends terminating in.oblique faces 24 adapted to fit the oblique faces of the abutments 17when the reaming bits or slips are in expanded or operating position asshown in Fig. 2; The reaming bits or slips 23 have cutting edges 25 andtail pieces or extensions 26 extending downward below the plane of thecutting edges; they are also each provided above the cutting edges withan opening 27 adapted to receive the end of the cross bar 13 and ontheir outer faces they are each provided with a recess 28 to receive theend of a pin 29 in the end of the cross bar. On their sides the reamingbits or slips are each provided with ribs 30 adapted to travel in thespace 22 and to engage and be guided by the guide rib 20. In order thatthe reaming bits or slips may readily pass the angle 16 atwhich theupper and lower surfaces 14. 15 of the wedge come avaioe together theirinner faces are concaved as shown at 31 and to further facilitate thefree passage of the reaming bits from end to end of the wedge the ribs30 are slightly eased off or cut away as shown at 32.

In the lower ends of the reaming hits or slips are formed holes oropenings 33. these holes being bored at such an angle that when thereaming hits or slips are at the lower end of the wedge as shown in Fig.1 the holes in the two reaming bits or slips will converge slightly frombelow upward. These holes are adapted to receive the slightly converginglegs 34 of a staple as shown in Fig. 1 by which the reaming bits orslips may be held together in retracted position.

The spring rod 10 is preferably formed at a suitable point between itsends with a shoulder 36 which is adapted to be engaged by the inwardprojecting ends 37 of trips 38 which are carried in recesses 39 formedin the reamer body above the abutments 17 The trips 38 are retained inposition by pins 40 extending through slots 41 in the trips, the slots41 being of sufiicient length to permit the trips to move sufficientlyto engage and disengage their ends 37 with the shoulder 36. The ends 37of the trips terminate in inclined faces 42 to 9 permit the shoulder 36,which also has inclined upper and lower faces, to pass the trips whenthe trips are not pressed inward.

The recesses 39 are preferably provided in their bottoms with openingsor perforations 43 extending into communication with the bore 11 topermit water and any fine sand to pass through.

When the tool is to be introduced into a well hole the reaming bits orslips are drawn down to the lower end of the wedge to the position inwhich they are shown in Fig. 1. against the upward pull of the spring '7and are held there temporarily by any convenient means as for instancebyinserting the legs 34 of the staple35 in the holes 33. The trips 38 arethen pressed inward to causetheir ends 37 to engage the upper face ofthe shoulder 36 and are held in such engagement by removable ring G asin the tool of my patent before referred to. The staple 35 may then beremoved if desired. The reaming bits or slips are thus held opposite thelower surfaces 15 of the wedge being so far contracted or brought inwardthat the tool will pass freely through the casing. As the tool entersthe casing the upper end of the casing will stop the ring G and thetrips will engage the inner walls .of the casing and hold the ends 37 ineneveuoe allowed to remain in position, as soon as one or the other ofthe reaming bits or slips strikes the shoulder at the upper end of thesmall hole below the casing, or any obstruction sufiicient to stop it,it will be freed from engagement with the staple and at the same timethe other reaming bit or slip will free itself from the staple whichwill drop off. The reaming bits or slips will thus be free to be movedto expanded position by the spring 7 and the tool is then ready for usein the usual manner of using an underreamer.

By the use of the Wedge as above described having upper and lowersurfaces of different angle a degree of expansion and contraction of thereaming bits or slips is socured much greater than that obtainable wherea straight wedge is used, without increasing the length of the wedge.For instance in a well in which 8% inch casing is used the straightwedge underreamer of usual length will enlarge the hole below casing to10 inches which is sufiicient to permit the casing to be lowered underordinary conditions, but is not adapted to enlarge the hole to a greaterdiameter. A tool of the present invention capable of passing freelythrough the 8?; casing when the reaming bits or slips are in contractedposition, that is when at the lower end of the wedge resting against thelower surfaces 15, is capable, when the reaming bits or slips are inexpanded position, that is against the abut-ments 17, of enlarging thehole to a diameter of 11 inches. This increased diameter is in somecases of great importance in order to enable the casing to passobstructions which would otherwise stop it as where the hole is crookedor where a ledge of rock is encountered immediately below soft materialin which bad caving has occurred.

The lower portions of the guide ribs 20 that is the portions oppositethe lower portions 15 of the surface of the wedge hold the reaming bitsinward against the possibility of outward swing which might be caused bystriking an obstruction or by lowering the tool rapidly through water. i

The spring rod 10 is preferably fiattened between the shoulder 36 andthe lower end of the rod as shown in-Fig. 12 so as to give increaseddepth of shoulder 36 for the engagement of the trips without materiallylessening the strength of the rod as would be done by turning down therod.

For some purposes it is desirable to drill a small hole andsimultaneously enlarge the drilled hole. For this purpose I may providethe underreamer with a bit 45 extending downward below the lower end ofthe wedge 2 as shown in Fig. 10. The bit in such case is provided belowthe apex of the wedge with an opening 46 of suflicient length and widthto permit the reaming bits or slips to pass through it after they aremoved down pastthe apex of the wedge. The housings 19 are extendeddownward to support the bit t5 the housing being of sufticient mass togive the necessary strength.

In the operation of under-reaming as the tool descends and causes thecutting ed es of the reaming bits to strike on the shoul erof materialto be cut away, the reaming bits will usually tend to stick in thematerial of the well wall by reason of the resistance of the materialand the pinching in due to this resistance, but as the tool is drawnupward after striking a blow, the Wedge is drawn slightly upward frombetween the reaming bits, relative movement of the wedge and reamingbits being, permitted by the yielding of the spring 7, and as the wedgemoves upward the reaming bits are drawn inward freeing them from thewall of the well hole. As the tool continues to rise the reaming bitsare brought up above the shoulder into the portion already reamed tofull diameter and are then at once returned to contact with theabutments by the contractlon of the spring.

It-will of course be understood that I do not desire to be limited tothe precise construction or arrangement shown or described, as it isobvious that changes in the detailsof construction and proportion andarrangement of parts may be made without departing from the spirit ofthe invention.

Having thus described my invention and explained the operation thereof,I claim as new and desire to secure by Letters Pat ent:

1. In an under-reamer the combination of a reamer body having a wedgeshaped portion adapted to receive and support reaming bits, the upperand lower portions of the surfaces of the wedge being at differentangles to the longitudinal axis of the wedge, guide ribs formed in therealner body adjacent the upper portions of the surfaces of 'the wedge,and extending below said upper portions, reaming bits provided withmeans for engaging said guide ribs, and means for moving the reamingbits from one portion of the wedge to the other portion.

2. In an under-reamer the combination of a reamer body having a wedgeshaped portion adapted to receive andsupport reaming bits, the upper andlower portions of the surfaces of the wedge being at different an glesto the longitudinal axis of the wedge, guide ribs formed in the reamerbody ad jacent and parallel tothe upper portions of the surfaces of thewedge, and extending below said upper portions, reaming bits pro videdwith means for engaging said guide ribs, and means for moving thereaming bits from one portion of the wedge to the other portion.

5;). In an under-reamer the combination of a reamer body having a wedgeshaped portion adapted to receive and support reaming bits. the lowerportion of the surfaces of the wedge being at a greater angle to thelongitudinal axis of the wedge than the upper portions, guide ribsformed in the reainer body adjacent the upper portions of the surfacesof the wedge, and extending below said upper portions, reaming bitsprovided with means for engaging said guide ribs, and means for movingthe reaming bits from one portion of the wedge to the other portion.

l. In an under-rcanier the combination of a reamer body having a wedgeshaped portion adapted to receive and support reaming bits, the lowerportions of the surfaces of the wedge being at a greater angle to thelongitudinal axis of the wedge than the upper portions. guide ribsformed in the reainer body adjacent and parallel to the upper portionsof the surfaces of the wedge, and ex tending. below said upper portions,reaming bits provided with means for engaging said guide ribs, and meansfor moving the reaming bits from one portion of the wedge to the otherportion. 7

In anunder-reainer the combination of a reainer body having a wedgeshaped portion adapted to receive and support reaming bits, the lowerportions of the Surfaces of the wedge being at a greater angle to thelongitudinal axis of the wedge than the upper portions, guide ribsformed in the reamer body adjacent and parallel to the upper portions ofthe surfaces of the wedge, and extending below said upper portionsadjacent to the lower portions of the surfaces, the spaces between saidguide ribs and the lower portions of the surfaces being wider at theupper ends of said spaces than at their lower ends, reaming bits rovidedwith means for engaging said guide ribs, and means for moving thereaming bits from one portion of the wedge to the other'portion.

6. In an under-reamer the combination of a reanier body having a wedgeshaped portion adapted to receive and support reaming hits, the upperand lower portions of the surfaces of the wedge being at differentangles to the longitudinal axis of the wedge, guide ribs formed in thereamer body ad acent the upperportions of the surfaces of the wedge, andextending below said upper portions, reaming bits provided with meansfor engaging said guide ribs, and having their inner faces concaved, andmeans for moving the reaming bits from one portion of the wedge to theother portion.

7. In anunder-reainer the combination of a reamer body having a wedgeshaped portion adapted to receive and support reaming hits, the upperand lower portions of the surfaces of the wedge being at differentangles to the longitudinal axis of the wedge, guide ribs formed in therealner body adj acent and parallel to the upper portions of thesurfaces of the wedge,'and extending below said upper portions, reamingbits provided with means for engaging said guide ribs, and having theirinner faces concaved, and means for moving the reaming bits from oneportion of the wedge to the other portion.

8. In an under-learner the combination of a reamer body having a wedgeshaped portion adapted to receive and support reaming bits, the upperand lower portions of the surfaces of the wedge being at differentangles to the longitudinal axis of the wed e, guide ribs formed in thereamer body ad acent and parallel to the upper portions of the surfacesof the Wedge and extending below said upper portions, adjacent to thelower portions of said surfaces, the spaces between said guide ribs andsaid lower portions being wider at the upper ends of said spaces than atthe lower ends, reaming bits provided with means for engaging said guideribs, and having their inner faces concaved, and means for moving thereaming bits from one portion of the wedge to the other portion.

This specification signed and witnessed this 19th day of October A. D.1909.

JOHN C. SWAN.

In the presence of CHAS. E. RIonooN, A. P. GREELEY.

